When blood vessels are damaged, cell fragments released from the bone marrow, called platelets, adhere to the walls of blood vessels and form clots to prevent blood loss. It is important to have adequate numbers of normally functioning platelets to maintain effective clotting, or coagulation, of the blood. Occasionally, when the body undergoes trauma, or when the platelets are unable to function properly, it is necessary to replace or transfer platelet components of blood into a patient. Most commonly, platelets are obtained from volunteer donors either as a component of a whole blood unit, or via plateletpheresis (withdrawing only platelets from a donor and re-infusing the remaining of the blood back into the donor). The platelets then are transferred to a patient as needed, a process referred to as “platelet transfusion”.
The platelets, like other blood products of humans or animals, has a potential risk of being contaminated with pathogens such as viruses. Consequently, recipients of platelet transfusion must face the risk of being infected with high risk viruses such as the AIDS virus and various hepatitis viruses.
Methods for preventing viral infection involved in the use of blood products have been developed. For example, a chemical deactivating method using a surfactant or methylene blue has been known as a method for deactivating viruses in blood products. However, any of these methods has problems such as denaturation of proteins, requirements for complicated procedures for removing used chemical substances, and remaining of chemical substances in the finished products. Accordingly, there still exist a need for methods that can effectively remove pathogens from stored platelets.